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Search Results: 1 - 10 of 140934 matches for " 朱玥明 "
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聚合物驱油剂的性能变化规律研究(I)——聚合物驱油剂的热稳定性研究
Study of Performance Changes of Polymer Flooding Agent (I)——Study of Thermal Stability of Polymer Flooding Agent
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Open Journal of Nature Science (OJNS) , 2013, DOI: 10.12677/OJNS.2013.12003
Abstract:
本文采用红外、动态光散射、流变、荧光技术,研究了老化时间、模拟水矿化度、老化温度对水溶性疏水缔合聚合物本体结构和溶液性质的影响,探讨了分子组成、构象变化对分子间缠结、疏水缔合等结构的作用,建立了不同矿化度下水溶性疏水缔合聚合物溶液的温度、老化时间相关的热降解二元动力学方程。实验结果表明,疏水缔合结构的存在使其在发挥抗盐、增稠作用时能够经受一定时间的考验,老化引起的水解程度的适度增加反而有利于聚合物的增粘性。
The effect of aging time, water salinity, and aging temperature on the structure and aqueous behavior of the water-soluble hydrophobically associating polymer is investigated by FTIR, DLS, rheological and fluorescence technologies. The influence of macromolecular composition and conformation on intermolecular entanglement and hydrophobically associating are explored. For different salinities, the thermal degradation binary kinetic equation with aging time and temperature are established. The results show that after shearing, the thickening effect will rise up in a certain time, due to the hydrophobically associating structure. And the thickening property is enhanced by moderate increase of hydrolysis level caused by aging effect.
混氢改善汽油机稀燃性能的试验研究
汪硕峰,纪常伟,张擘,,张旻
工程热物理学报 , 2010,
Abstract: 针对汽油机稀燃条件下循环变动大,燃料燃烧不充分的问题,本文在一台加装了电控氢气喷射系统的四缸汽油机上就混氢对改善汽油机稀燃条件下燃烧与排放性能的作用进行了试验研究。在发动机1400r/min,进气道绝对压力为61.5kPa的条件下,就1%与3%两种进气混氢体积分数对稀燃汽油机燃烧与排放特性的影响进行了研究。试验结果表明,稀燃时发动机制动热效率随混氢分数增加而提高;滞燃期与速燃期随混氢分数增加而缩短;发动机稀燃极限所对应的过量空气系数由原机的1.45提高至混氢1%与3%时的1.55和1.96。混氢后发动机HC与CO排放降低,但NO_x排放有所升高。
支扩方对支气管扩张症模型气道炎症及细胞因子影响
万毅刚,曹世宏,毕建军,云华,,
中国中药杂志 , 2002,
Abstract: 目的:探讨支扩方与氧氟沙星对支气管扩张症(支扩)模型气道炎症及细胞因子的影响。方法:建立绿脓杆菌大鼠支扩模型,以支扩方与氧氟沙星进行干预,比较支扩方与氧氟沙星对支扩模型血炎症细胞密度、气道分泌物排泌量、气道冲洗液细菌量、气道组织细胞因子(IL8,TNFα)、气道组织病理学的影响。结果:支扩方对炎症细胞密度、气道分泌物排泌量、气道组织IL-8,TNF-α的作用优于氧氟沙星(P<0.05)。而氧氟沙星对气道冲洗液细菌量的作用优于支扩方(P<0.05)。两者对气道组织病理学影响的差异无显著性。结论:支扩方可能是通过抑制气道组织IL-8,TNF-α活性,减少气道分泌物排泌量,降低炎症细胞密度,减轻气道炎症反应,实现抗炎抑菌作用。
弗吉尼亚鼠刺叶片中稀少糖醇生物转化及分离制备
窦德泉,曾艳,,刘灿,孙媛霞
食品科学 , 2014,
Abstract: ?为探讨使用鼠刺植物制备稀少糖醇的可能性,以弗吉尼亚鼠刺叶片为原料,热水提取其所含的稀少糖及糖醇,使用产酸克雷伯氏菌静息细胞对提取物的单糖类物质进行生物转化,再利用絮凝、离子树脂色谱分离以及乙醇结晶连用手段对转化的提取物进行纯化,最后使用核磁共振谱对获得的稀少糖醇进行分析鉴定。液相色谱分析结果显示弗吉尼亚鼠刺叶片提取物含有稀少d-阿洛酮糖和蒜糖醇,其质量分数分别为27.86%和7.86%;利用制备的产酸克雷伯氏菌的静息细胞进行60h催化反应后,提取物中86%的d-阿洛酮糖转化为蒜糖醇,其余被细胞代谢消耗。多种分离纯化手段的联合使用,能有效去除杂质和色素,获得蒜糖醇纯品。
产褐藻胶裂解酶菌种的筛选、鉴定及发酵条件优化
陈朋,,韩文佳,门燕,贾士儒,孙媛霞
食品科学 , 2015,
Abstract: ?以褐藻酸钠为唯一碳源,经多次富集和驯化,从养殖场腐烂海带中筛选到一株高产褐藻胶裂解酶的菌株alg07。依据菌体形态、生理生化特征和16srrna基因序列分析,归属于芽孢杆菌属(bacillus),命名为bacillusweihaiensisalg07。通过单因素试验和正交试验,确定菌株alg07的最佳发酵产酶培养基成分:褐藻酸钠9g/l、蛋白胨1g/l、酵母粉3g/l、nacl5g/l、mgso4·7h2o1g/l、kcl5g/l、cacl24g/l;最佳发酵产酶条件为:250ml三角瓶装液量40ml、培养温度30℃、初始发酵ph6.5、接种量0.5%、摇床转速180r/min、培养时间24h。在优化后的培养条件下,褐藻胶裂解酶活力由35u/ml提高到563u/ml。
以d-果糖为原料利用新型异构酶转化生产d-阿洛糖
柏玮?,,门燕?,李晓波?,何森健?,孙媛霞?
生物工程学报 , 2012,
Abstract: 稀少糖是自然界中含量稀少、化学合成困难的一类低热量单糖。d-阿洛糖是一种重要的稀少己醛糖,其具有减少活性自由基、抑制癌细胞增殖等独特的生理学功能。因此,以微生物发酵生产d-阿洛酮糖-3-差向异构酶(dpe)和l-鼠李糖异构酶(l-rhi)转化生产d-阿洛糖,成为近几年来国际研究的热点之一。文中分别克隆了来源于解纤维梭菌clostridiumcellulolyticumh10的dpe基因以及来源于枯草芽胞杆菌bacillussubtilis168的l-rhi基因,并分别使其在宿主菌b.subtilis及大肠杆菌escherichiacolibl21(de3)中得到了表达。进一步利用镍亲和层析和阴离子交换色谱等手段对这两种酶进行了纯化,并对这两种纯化后酶的转化能力进行了分析测定。结果表明,以d-果糖为原料利用两种异构酶依次转化获得d-阿洛酮糖及d-阿洛糖,其两步转化效率分别为27.34%和34.64%。
含瓦斯煤全应力–应变过程中力学及渗流特性试验研究
Experiment Study on Mechanics and Permeability of Coal Containing Gas under the Total Stress-Strain Tests
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王倩,, 王维忠
Mine Engineering (ME) , 2015, DOI: 10.12677/ME.2015.34026
Abstract:
利用自行研制的含瓦斯煤热流固耦合伺服渗流试验装置,以原煤试样为研究对象,进行含瓦斯煤全应力–应变渗流试验。研究表明:在连续加载过程中,含瓦斯煤的应力–应变关系可以分为四个阶段:初始压实阶段、弹性阶段、屈服破坏阶段、破坏后阶段,这四个阶段煤样的应力–应变关系有较大差异;含瓦斯煤的弹性模量先下降后稳定,在破坏后快速下降;泊松比先下降后缓慢上升,在破坏后快速上升;含瓦斯煤的轴向应力与渗透率随轴向应变的变化规律基本呈相反的趋势;含瓦斯煤渗透率与体积应变密切相关,但分析发现,煤样体积最小时,其渗透率不是最低。
A self-developed device called the coal-containing heat solid coupling servo seepage device is used to do the total stress-strain tests of coal samples. The result shows: In the process of continuous load, the stress-strain relationship of coal containing gas can be divided into four stages: the initial com-paction phase, the elastic phase, the yield and damage phase, the post-failure phase. The stress- strain relationship of these four phases makes a big difference; elastic modulus of coal containing gas first decreases and then keeps constant; it declines rapidly after destruction; the Poisson's ratio firstly dropped after a slow rise, and it raised rapidly after destruction. With the change of axial stress, the axial stress of the coal containing gas and its permeability is opposite. Permeability of the coal containing gas is closely related with its volumetric strain. But we have analyzed and found that, the permeability of the coal is not the lowest when its volume is the smallest.
水压作用对裂隙岩体断裂行为影响研究
Study on the Effect of Hydraulic Pressure on Fracture Behavior of Fractured Rock
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王倩,, 王维忠
Mine Engineering (ME) , 2016, DOI: 10.12677/ME.2016.43017
Abstract:
为研究在地应力场与水压耦合作用下裂隙岩石破坏特性,利用MTS815岩石力学测试系统,并结合柱塞泵水压加载装置,对含有预制裂隙的混凝土试样加载预应力后,进行有无水压作用单轴循环加卸载压缩破坏对比试验。试验结果表明:有水压作用的试件在加载初期便出现初始裂隙,而无水压时试件往往在塑性区或接近塑性区时出现初始裂隙,两者的破坏模式也不相同,在有水压作用时,试件是由于水压引起的表面裂纹扩展而导致破坏,而无水压时则是因为试件内部损伤微裂隙扩展引起的失稳破坏;然而两种条件下的试件强度相差不大,但其破坏过程中产生的耗散能却高于后者。
In order to study the failure characteristics of rocks under coupling effect of ground stress field and seepage field, MTS815 rock mechanics test system combined with plunger pump hydraulic loading device are used to load water pressures on concrete samples containing precast crack. After that, uniaxial cyclic loading and unloading compression failure contrast experiments are conducted with the seepage field and without the seepage field. The results show that: specimens with the seepage field present initial crack at the initial stage of loading, but species without seepage field present initial crack always in plastic zone or close to plastic zone. The failure mode under both conditions is not the same. The failure is caused by surface crack expand under the water pressure effects, and without water pressure it is caused by the internal damage and micro cracks extend. The strength under the two kinds of conditions is equivalent, while the dissipated energy in the process of failure is higher than those without seepage field.
Progress on molecular biology of trehalose synthase-A review
海藻糖合酶的分子生物学研究进展

Yueming Zhu,Jun Zhang,Laijun Xing,Mingchun Li,
,张峻,邢来君,李明春

微生物学报 , 2009,
Abstract: Trehalose synthase inverts maltose into trehalose, and plays a very important role in trehalose industrial production. Here we reviewed the recent progress on studies of molecular biology including the cloning of trehalose synthase gene, gene engineering application, structure and catalytic mechanism and the role of the enzyme in vivo.
考虑量测误差计及等值参数物理约束的外网静态等值方法
郭文鑫,李世,,李钦,,卢建刚,颜伟
电网技术 , 2012,
Abstract: 受最小二乘估计模型的多解影响以及量测误差的随机影响,依赖于内网实测信息的两端口外网静态等值参数估计方法,其外网等值参数值存在不稳定和不满足物理特征的现象。为此,在其等值电路模型及其等值参数的2阶段估计方案基础上,增加边界节点电压及内网等值负荷电流的量测状态变量及其量测方程,同时增加了外网等值参数的物理约束,以改进最小二乘外网等值参数估计模型。算例结果验证了该方法的有效性。
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